In this study, we presented lemma selecting standard and method according to dictionary planning agenda in dictionary compilation. Some solutions for problems on lemma selecting method are discussed. The proposed method and solutions are applied to Yonsei Contemporary Korean Dictionary Compilation as an example. In contemporary dictionary compilation, lemma selection is conducted based on lemma list and word frequency. Management and analysis on frequency data as well as interpretation of frequency data results are main issues when applying corpus approach. Accordingly, we presents classification of lemma type in Yonsei Contemporary Korean Dictionary. Method and its application on lemma list construction with respect to lemma type are also presented. Chapter Ⅱ reviews lemma selection basis adopted by existing dictionary and research. Significance of word frequency based lemma selection and some issues on word frequency based approach are also discussed. In Chatper Ⅲ, we presents features of Yonsei Contemporary Korean Dictionary, and discusses lemma list constructing standard for Yonsei Contemporary Korean Dictionary. Chater Ⅳ presents classification and selecting methods, some problems, and supplementation on lemmas of Yonsei Contemporary Korean Dictionary. Constructing and supplementing method for integrated Data base for lemma selection is presented in Chapter Ⅴ.